Loudness n. america march 2012

Act CALM and Carry On!Act CALM and Carry On!Loudness, recommendations,

Legislation & compliance

BS.1770, ATSC A/85, CALM Act

Andrew Sachs

VP. Product Management

Jennifer Knutel

Sr. Dir of Marketing

• Why Loudness?

• What is Loudness ?

– Specification - BS.1770

– Recommended Practice –

Agenda

• ATSC RP A/85 & Dialnorm

– Regulation –

• CALM Act, FCC 11-182A1 Report and Order

• How to comply

• Volicon loudness solutions

• Q&A

Why Loudness?

• Analog (FM) sound world of yesterday

• Dynamic range limited:

– Upper end by modulation limits and

adjacent channel

– Lower end by noise floor

Channel

Upper

Modulation

Limit

Noise

Floor

Peak

target

Typical

Program

Range

• Operators leveled programming using peak

meters

• Programs were perceived as similar levels

• Consumers do not feel they have to adjust

the volume

Floor

Peaks leveled

Across Programs

Tolerable

Perceived

Differences

One

Volume

Setting

Why Loudness?

• Digital Sound

• Much greater dynamic range than analog

• Better transmission methodsAnalog

Digital

• Metadata on dynamic range

• Able to create the “theater experience”

+40dB more

dynamic range

Why Loudness?

– Added dynamic range/headroom can be used

differently by different types of content

Use Dynamic Range Make content LOUDERNo Change

Create theater

experience.

Movies, Music

..

Talk or News

programs

People pay more

attention

Advertisers

who want your

attention

Why Loudness?

• Tragedy of the Commons

• Level according to peaks

• Users pay more attention to loud content

– Advertising recognition is higher

– Advertisers KNOW and use this

Difference

is much

larger

than

with analogPGM

Ad

PGM

Ad

PGM

– Advertisers KNOW and use this

• Users feel they need to adjust volume

– Detracting from their overall QoE

– Solution:

• Level according to “loudness perception”

• Content flexibility with good user experience

– Now, what is “loudness perception”?

Volume

Adjustments

No Volume

Adjustments

What is Loudness?

Specification

What is loudness?

Recommended

BS.1770-1/2 LKFS gated

Recommended

Practices

How to use loudness

Regulation

How it is enforced

R128Tech 3341/2/3 A/85 RP TR-B32

What is Loudness? Specification

• Goal of specification: Objectify the Subjective

• Result : ITU Recommendations on Loudness Measurement

– BS.1770-1 (09/2007) - Algorithms for Loudness and true peak

– BS.1770-2 (03/2011) - Added gating – more on this later– BS.1770-2 (03/2011) - Added gating – more on this later

• Not all frequencies are created equal

– K-weighting

– Upper frequencies effect amplified up to 4dB

– Lower frequencies attenuated (~80Hz 3dB)


• Not all channels are created equal

– Left (L), Right (R) and Center (C)

• 1.0 weighting (+0.0 dB)

• Stereo and 5.1 will measure the same

Rs

L

C

R

1.0 (0.0 dB)

– Rear Surrounds are 1.41 weighted (+1.5 dB)

• Sounds from side/back perceived louder

– LFE Channel (.1) not counted

• Low frequency content tends not to affect loudness perception

LFE (.1)

RsLs

1.41

(+1.5dB)1.41

(+1.5dB)

0.0 (- ∞ dB)


• One measurement summed for entire audio track

– Mono, Stereo, 5.1

– Stereo channels will measure the same in 5.1 (same weights)

OR ORL K-WeightMean

Square0 dB

R

C

Ls

Rs

K-Weight

K-Weight

K-Weight

K-Weight

Mean

Square

Mean

Square

Mean

Square

Mean

Square

0 dB

0 dB

+1.5dB

+1.5dB

∑One

LOUDNESS

Value


• How to not count periods of silence or very low levels?

– Counting periods of silence would “lower the loudness level”

– Could be gamed by advertisers – Yell for 10s, silent for 20s

– Gate to only measure relevant audio

• BS.1770-2 added a cascaded relative gate of -10dB GATE• BS.1770-2 added a cascaded relative gate of -10dB

– Do not count periods that are > 10 dB lower (8dB in R128 original)

– Determined every 10Hz with 400ms windows � 75% overlap

Ungated

average

Higher

Gated

average

-10dB gate

--10dB

One loudness value,

AFTER gating

?

gate


• Meausre for the entire length of the content

� Short form -< 2 minutes ad or promo

� Long form - > 2 minutes program or promo

� Overall channel - time (e.g. 6h, 1d, ..)� Overall channel - time (e.g. 6h, 1d, ..)

• Into one LKFS measurement (dB scale)

� Logarithmic K-weighted Full Scale

� FS – 0.0 is Digital Full Scale (max)

� E.g. -10 LKFS is 10x more than -20 LKFS

-x.yz

LKFS


• Lack of international agreement on Gate

• EBU, BS.1770-2, BS.1864 �

– Cascaded, -10dB level based

• ATSC RP A/85 �

– Short form – no gate(yet), measure entire content– Short form – no gate(yet), measure entire content

– Long Form (>2m) – “Anchor Element”

– “Anchor element” suggested to be “Dialog Level”

• Measure just the dialog portion of the content

• Except when not practical (music program)– then measure all content

• Use the same gating your regulator/partner

– Dialog/level, short/long interval, level gate #

What is Loudness ? Recommended Practice

• ATSC RP A/85 July 2011

– Does not incorporate BS-1770-2 (March 2011)

– Specifically, does not include of level gating

– Hints that future versions may change

• ATSC RP A/85 does say:

– Target Level - -24 LKFS

– Utilize DIALNORM properly.

– Short Form (<=2m) measurement – no gating, measure entire asset

– Long Form (>2m) measurement – measure dialog as “anchor element”

-24 LKFS ��

What is Dialnorm? DIALog NORMalization

AC-3 (DD) metadata that allows programs originated with different levels

to be decoded with the same perceived loudness. (originally for dialog)

Asset

Loudness

Measurement

-24 -31-31

-1

-12

-24

Higher Level �

Higher

Attenuation

All properly tagged assets measure -31 LKFS at the output of the STB

-24 LKFS before dialnorm is applied is the same as -31 LKFS after dialnorm

-24

LKFS

Asset tagged with proper

dialnorm

-24 -31

AC-3 decoder

applies dialnorm

[1..31]

-31

LKFS

-31

24

“Agile” Dialnorm in Operation

• Assets of different levels with proper, possibly varying, dialnorm

– Outside production, network feed, advertising, breaking news…

– By originating source or at point of ingest

-27

LKFS 27-1

-12LKFS

-17

LKFS

-24

LKFS

-29

LKFS

17

24

29

Control

& Encode

27 17

Dialnorm

Distribution

-31

AC-3 decoder

applies dialnorm

-31

-12

-24

-31

Everything

sounds

the same!!

What should you do with Dialnorm? Fixed!

• Fixed Dialnorm - Do NOT do agile dialnorm

• Content is normalized to -24 (or other fixed):

24

– Network Feeds – Monitor over long periods. Issue corrective actions with examples content with non-compliance. Networks have same incentives.

24

24

24

compliance. Networks have same incentives.

– Tape based assets – Measure loudness and compensate on mixing.

– File based assets – Measure and correct to -24 LKFS.

– Live Feeds – Target mixing for dialog (DIALNORM). Monitor loudness for large discrepancies. Most leeway given on levels of live content.

What should you NOT do with Dialnorm?

• Do not

– Fix assets levels on the fly - exception being live programming mixing.

– Correct embedded commercials - too late by the time – Correct embedded commercials - too late by the time they are delivered.

– Wait- Do not wait that is. Utilize monitoring and the next 8 months to take corrective action

Like a factory, ensuring quality inputs and

process control will ensure a quality product.

What is Loudness ? Legislation

• CALM ACT (Commercial Advertisement Loudness Mitigation)

– Sept 2010: “… ensure that commercials will be played at the same volume as the program. ”

• FCC 11-182A1 Report and Order – Dec 13, 2011

11-182A1

CALM Act


– Rules: Appendix A (pp.38-45) key portion of the document

– Comply to A/85 (set DIALNORM)

– Enforced December 13, 2012

– Covers US Broadcasters and MVPDs (Cable, Satellite, IPTV)

– Commercials – embedded or inserted

Commercials cannot be more than 2dB over channel



– FCC will “…initiate an investigation when we receive a pattern or trend of consumer complaints…”

– FCC will request certification and resolution

– Station must respond within 30 days following inquiry

– From historical closed caption compliance, complaints may come in 30+ days after broadcast


• Inserted commercial compliance (TV or MVPD)

– Install, utilize and maintain equipment that measures the loudness of the content. Ensure dialnorm is set properly.

– Provide records (testing, periodic maintenance) showing equipment is working properly.equipment is working properly.

– Certify no knowledge of violations or that any violation has been corrected promptly

– Certify own equipment is not at fault for a trend of complaints


• Embedded commercial compliance options

– Network/programmer provides certification

– Annual spot checks (24 hours/network, no notice – Annual spot checks (24 hours/network, no notice to network, measure commercials relative to channel).

– Real time processor - From FCC 11-182: “…stations, MVPDs, content providers and consumers disfavor real-time processing due to its harm to overall audio quality.” “rarely do so”


• Where does the blame fall in the chain?

– Programmer, Network, Broadcaster, MVPD?

RegulatesProtectsEnforces

Network

MVPDCable

Satellite

IPTV

Broadcaster

ProgrammerCable

Network

Blame

Observer Loggers with Loudness

• Software module available on

– Observer, Observer TS, RPM

• Observer family of products are loggers at the core

– Records audio, video & loudness measurements continuouslycontinuously

– 3 to 365 days of storage

• Logger + measurement is very powerful

– Speeds troubleshooting, unambiguous affidavit

– Eliminates Network � Station � MVPD back and forth

Loudness logging is not a sea of numbers. It means

recording the audio, video,

and the loudness measurements.

For more information please

contact us ([email protected])

and come see us at

NAB Booth SU5715

+1 781 221 7400

Andrew Sachs

VP. Product Management

[email protected]

Jennifer Knutel

Sr. Dir of Marketing

[email protected]

Loudness n. america march 2012

Technology

Transcript of Loudness n. america march 2012